201 oocytes in meiosis i have a large nucleus

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Unformatted text preview: is I have a large nucleus ( germinal vesicle). Many oocytes contain localized determinants, typically mRNAs. For historical reasons, the less yolky end of the oocyte is called the animal pole; the opposite is the vegetal pole. The Ovary One follicle per ovulatory cycle matures in humans (follicular dominance). Dominance may involve local production of growth factors by the follicle that “wins” Campbell et al, 5e, Fig. 46.13 Oogenesis in Mammals Gilbert, 9e, Fig. 16.31 Oogenesis in Mammals The mature follicle must rupture to release the oocyte, which normally is swept into the Fallopian tube Gilbert, 9e, Fig. 16.31 Female Reproductive Structure fimbriae Fallopian Tube Fimbriae sweep the oocyte/cumulus complex into the open end of the Fallopian tube Adapted from Campbell et al, 5e, Fig. 46.9 Fallopian Tube: Hamster Opening of fallopian tube Stained hamster oocyte/cumulus complex Ovulation: Hormonal Feedback Control The hypothalamus stimulates the anterior pituitary via the release of gonadotropin releasing hormones (GnRHs) specific for particular gonadotropins, e.g., luteinizing hormone (LH) or follicle stimulating hormone (FSH) Purves et al, 6e, Fig. 42.14 Ovulation: Hormonal Feedback Control Gonadotropins positively regulate cells in the ovary. Estrogen is made by connective tissue cells in the ovary. Progesterone is made by the follicle, but especially by the remnant of the follicle (corpus luteum). Estrogen and progesterone inhibit hormone production by the hypothalamus and pituitary. Progesterone stimulates thickening of the uterine lining. Purves et al, 6e, Fig. 42.14 Control of Ovulation: Hormonal Regulation Gilbert, 7e, Fig. 19.30 Control of Ovulation: Hormonal Regulation Gilbert, 7e, Fig. 19.30 Human Chorionic Gonadotropin & Progesterone hCG progesterone supports endometrium hCG is made by the embryo and stimulates the corpus luteum to inhibits contraction maintain progesterone production. firms cervix Ulmann et al...
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This note was uploaded on 11/08/2013 for the course ZOOLOGY 470 taught by Professor Hardin during the Fall '12 term at University of Wisconsin Colleges Online.

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